1. Field of the Invention
The present invention is related to a fluorescence detecting apparatus and a fluorescence detecting method for quantitatively or qualitatively analyzing target substances within samples.
2. Description of the Related Art
Plasmon sensors that quantitatively analyze substances within samples using the principle of the surface plasmon resonance phenomenon employing evanescent waves are known (refer to Japanese Unexamined Patent Publication No. 10 (1998)-239233, for example). Japanese Unexamined Patent Publication No. 10 (1998)-239233 discloses that a light beam is irradiated onto the interface between a prism and a metal film, formed on a surface of the prism, that contacts a sample at a total reflection angle. The reflection angle of the light beam which is totally reflected at the interface is detected, to quantitatively analyze a substance within the sample. Further, this patent document discloses that a light source and a light detecting unit are movable, such that samples contained in a plurality of sample containers can be quantitatively analyzed.
In addition, fluorescence detecting apparatus that utilize the aforementioned evanescent waves have also been proposed (refer to Japanese Unexamined Patent Publication No. 2009-128152, for example). Japanese Unexamined Patent Publication No. 2009-128152 discloses that a detection target substance is quantitatively analyzed by detecting fluorescence which is generated when the detection target substance, which is labeled by fluorescent labels, within a sample container is excited by evanescent waves. Further, this patent document discloses that a light source is movable in order to enable adjustment of incident angles with respect to a metal film.
In the fluorescence detecting apparatus disclosed in Japanese Unexamined Patent Publication No. 2009-128152, a micro flow channel, through which a sample is caused to flow, and the metal film are provided in an analysis chip. Different analysis chips are employed for different samples, and the analysis chips are discarded after use. The analysis chips are produced to be of a predetermined size. However, there are cases in which dimensional shifts occur due to manufacturing errors. There is a possibility that the irradiation position of an excitation light beam and the position of the metal film will be shifted due to these dimensional shifts, leading to variations in the intensities of detected fluorescence. As a result, there is a possibility that the accuracy of analysis will deteriorate. Similarly, there are individual differences among apparatuses in the irradiation position of the excitation light beam due to manufacturing errors. Thus, there is a problem that the accuracy of analysis will deteriorate.